Well system and method for controlling the production of fluids

ABSTRACT

Embodiments of the present invention allow the placement of a stand alone device (valve) along a flow path, without a physical connection to the surface or reliance on the borehole for signaling, to provide a means to control the flow between reservoirs. This is achieved using a valve located in the flow path that can be actuated without sending signals down the borehole or well path and thereby eliminating the need for complicated signal lines and or fluid columns to actuate the valve.

FIELD OF THE INVENTION

The present invention relates to methods and devices for recoveringfluids from subterranean formations, and in particular, a system and amethod for recovering hydrocarbons by means of individual ormulti-lateral wells drilled to connect a distant reservoir to asubsurface zone.

BACKGROUND

It is generally known that methods for drilling wells close to anotheroriginate from the practice of drilling relief wells or the practice offield redevelopment where a second or third generation of drilling fromexisting well stock is required to enhance the recovery of the nearbyoil or gas. Methods for drilling multiple wells which increaseproduction from one well without injection from other wells have beenproposed before.

U.S. Pat. No. 6,729,394 and U.S. Pat. No. 6,119,776 are examples ofthis. U.S. Pat. No. 6,729,394 describes the use of a horizontal wellnetwork for producing low mobility oil, where at least one horizontalwell is used as to allow fluids to move from one part of the producingformation to another and closer to the final production well. U.S. Pat.No. 6,119,776 describes the use of an intersecting angled and verticalwell, in which the vertical well being used to withdraw the fluid thatwas originally contained in the angled well, combined with the optionaluse of a third well from which fractures are generated to the secondwell. However, practice of the methods and system disclosed by theforegoing art can be expensive and often requires the employment ofrelatively complicated procedures.

The prior art does not use multiple wells to produce from onehydrocarbon reservoir to another, but instead uses the reservoir lengthas a purposeful flow path. Furthermore, existing flow control devices(e.g., valves) use the well to transmit a signal along the borehole.However, controlling the flow between different reservoirs is stillevolving and one aspect that can be improved is communication to a flowcontrol device that has been along the wellbore. The purpose of the flowcontrol is to block unwanted fluids, such as water, gas, or oil, fromcoming to surface. Methods like 4-D seismic and others to detect theencroachment of such fluids already exist. Because of various drawbackswith designs that are well-known in the art, it is not desirable to sendsignals along the borehole to the flow control device. Embodiments ofthe present invention address the known deficiencies for communicatingwith a valve along the borehole and, as such, do not require thewellbore as the signal path.

SUMMARY OF THE INVENTION

In accordance with various embodiments of the present invention theprimary reservoir is connected to the marginal reservoir either bydrilling a bridging well adjutant to the primary well or extending theprimary well. A downhole production system for producing and controllinghydrocarbon from primary and marginal reservoir,

In accordance with various embodiments of the present invention, adownhole production system comprises a wireless transmitter thattransmits a wireless signal through the formation from a locationexternal to the borehole. A valve is located along a flow path betweentwo reservoirs. A sensor is adjacent to the valve and capable ofdetecting the wireless signal, wherein the valve is actuated in responseto the detection of the wireless signal by the signal detector.

Certain embodiments of a method for actuating a flow control devisecomprise several steps, which are as follows: (i) placing a flow controldevice between two reservoirs; (ii) transmitting a signal from a surfacelocation to a borehole through a strata; (iii) detecting the signal;(iv) communicating to the flow control device in a preset coded sequenceadapted to actuate the valve; and (v) actuating the flow control devicewhen the sensor receives the signal.

Moreover, embodiments of a method of producing subterranean hydrocarbonscomprises of the following steps: (i) drilling and completing a primarywell for producing a primary reservoir; (ii) drilling at least oneauxiliary well adjacent to the primary well; (iii) connecting theprimary reservoir to the marginal reservoir by extending the primarywell; (iv) completing the primary well to control fluid communicationbetween the primary reservoir and the marginal reservoir; and (v)placing a flow control device along a flow path between the primaryreservoir and the marginal reservoir.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a sectional view of a well with multiple producingintervals in sequence and a means to communicate to a valve locatedbetween the reservoirs without using the borehole.

FIG. 2 illustrates wellbores intersecting a plurality of productionzones.

FIG. 3 is a sectional view similar to FIG. 2, but illustrating analternate flow control valve.

FIG. 4 is a sectional view similar to FIG. 3, but illustrating a flowcontrol valve in a well requiring sand control.

FIG. 5 shows a schematic diagram of a multi-zone sand face completionrequiring more than one flow control valve and a communication line andcable.

FIG. 6 shows a schematic illustration of a sectional view of amulti-lateral wellbore with a plurality of production zones.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to providean understanding of the present invention. However, it is to beunderstood by those skilled in the art that the present invention may bepracticed without these details and that numerous variations ormodifications from the described embodiments may be possible.

In the specification and appended claims: the terms “connect”,“connection”, “connected”, “in connection with”, and “connecting” areused to mean “in direct connection with” or “in connection with viaanother element”; and the term “set” is used to mean “one element” or“more than one element”. As used herein, the terms “up” and “down”,“upper” and “lower”, “upwardly” and downwardly”, “upstream” and“downstream”; “above” and “below”; and other like terms indicatingrelative positions above or below a given point or element are used inthis description to more clearly describe some embodiments of theinvention. Moreover, the term “sealing mechanism” includes: packers,bridge plugs, downhole valves, sliding sleeves, baffle-plugcombinations, polished bore receptacle (PBR) seals, and all othermethods and devices for temporarily blocking the flow of fluids throughthe wellbore.

An embodiment of the present invention provides a system and method forcontrolling the flow of fluids that migrate through the subsurface froma distant marginal reservoir to one or more production zones of theprimary reservoir. The method of producing subterranean hydrocarbonscomprises of drilling and completing a primary well for producing aprimary reservoir. At least one well adjacent to the primary well willalso be drilled. The primary reservoir is then connected to the marginalreservoir by extending the primary well. With reference now to thefigures, and in particular to FIG. 1, a well (3) with producing interval(4) connects separate hydrocarbon intervals (5, 6) below the surface (1)to the surface facilities (2). According to the invention, a flowcontrol device (e.g., a sleeve valve, ball valve, flapper valve, diskvalve, choke valve and so forth) (7) is placed between the intervals (4,5 and 6) that can be used to close off flow between the intervalswithout any physical connections to the surface. The migration of fluidfrom one interval to the next can effectively drain the produced fluidwithout having to drill a separate well from surface and still maintaincontrol of the movement from the one interval to the next. While certainembodiments are described herein, for subsea operation, the presentinvention includes other embodiments employing the same systems andmethods for land use.

In this embodiment, with reference to FIGS. 1 and 2, the flow controldevice (14) can be placed along the flow path in the casing (13) betweentwo or more reservoirs, In the open state, the flow control deviceallows the fluids from one reservoir (4, 5, 6) to flow into a differentreservoir (4, 5, 6) until such time as the operator decides it is timeto stop the flow or choke the flow between the reservoirs. In thisapplication, it can also allow the purposeful drilling of a well toconnect one side of a reservoir (5) to a second nearby reservoir (6) andsubsequent plugging and abandoning of the upper section to surface ofthe subject well thus only contain the flow in the subsurface betweenthe two reservoirs (5 and 6). This then provides an enhanced flow pathbetween reservoirs. The flow control device (14) placed along the flowpath can be actuated later in the life of the field to shut off or chokethe flow between the reservoirs. In one embodiment the flow controldevice (14) is a stand alone device with no physical connection to thesurface and no reliance on the wellbore to detect a signal. This wouldeliminate the need for signal lines and/or fluid columns to actuate thevalve. This in turn, yields a significant reduction of installationcosts, thus reducing the cost of the development of the reservoir orfield.

With reference to FIG. 1, many signals (8) that are sent from surfaceare transmitted subsurface through the strata (29). The signals (8) canbe used to communicate to the flow control device (7) in a pre-set codedsequence that once understood by the flow control device (7) can actuatethe flow control device (14) to open or close or choke position. In someembodiments, a wellbore is not needed to transmit the signals to actuatethe flow control device (7).

Referring to FIGS. 2 through 6, an existing well (3) has a producinginterval (10) with a casing (13) and a production conduit (15). In oneembodiment a sand screen (17) is provided within each of the intervals(10, 11, 12) allowing fluids to be produced while preventing sand toenter the production tubing. The production intervals are separatingfluidically by sealing elements (16). Alternately a slotted pipe isprovided in place of screen. Yet in another embodiment the hole is linedwith casing or liner, cemented and perforated.

According to the invention, a second well (9) is drilled into anotherreservoir that is positioned further from the surface facilities. A wellmay be drilled through the wellhead (28) and through a formation toextend a structural casing (13) through the formation. A new well (9) isdrilled to connect the bypassed marginal reservoir (11) to the existingreservoir (10). A casing (13) is run to the top of the formation. Thesecond well (9) is plugged using a sealing element (18) above theformation interval (11) to provide a barrier. The sealing element mayeither be permanent, or such that the well can be reentered at a lattertime should it be necessary.

The reservoir (11) through the new well (9) is produced through the sandface completion and then injected into the existing reservoir (10).

In the example in FIG. 2, a ball type flow control valve (14) is runwith the well completion to regulate the flow from the reservoir (11) tothe existing reservoir (10). Referring to FIG. 3, a sleeve type flowcontrol valve (19) is run with the well completion. Referring to FIG. 4,the sleeve type flow control valve (19) is incorporated in the sandscreen (17). FIGS. 2 through 6 illustrate a sensor module (20) that isshown in the valve (14 and 19) to actuate the valve.

In some embodiments of the present invention, the power to the flowcontrol valve (14, 19) and downhole sensors (20) is supplied by adownhole power generator (21) which is run with the valve. A remotecoded signal or command is sent from the surface. A long life battery,fuel cell or other type of power supply could be run in place ofdownhole power generator (such as an inline turbine).

Depending on the particular embodiment of the invention, electromagneticcommunication, acoustic communication, pressure pulse, electronic signalcommunication in or along the casing or tubing, mud pulse communication,or seismic communication may be used. Thus, many different communicationtechniques may be used to communicate between the surface and the valve,in accordance with the possible embodiments of the invention. Forexample, an acoustic wave transmitter used in a wellbore typically willgenerate compressional waves, shear waves, and other types of waves whenthe acoustic transmitter is actuated. The compression wave is refractedin the formation surrounding the borehole and propagates through aportion of the formation surrounding the borehole. The acoustic wave isthen reflected or partially reflected from the formation into thesensor, which detects and measures the acoustic wave by two or morereceivers. The sensor (20) in the valve (14, 19) first detects thissignal and then the signal is processed by microprocessor in the valveand sent to valve actuator for actuation of the valve. Many signals thatare sent from surface through the subsurface and rock strata can be usedto communicate to the valve (14,19) in a preset coded sequence that onceunderstood by the valve (14,19) can actuate the device to open or closeor choked position.

An alternate embodiment of a method for sending signals from the surfaceto actuate the valve would require the downhole sensors to sense variousreservoir parameters such as pressure, flow, temperature, fluid density,fluid viscosity, or PH, and feeds the data to the downhole processorwhich processes the data and makes a logical decision to send a propercommand to the valve actuator for actuating the valve. A well bore isnot needed to transmit the signals to actuate the valve. It is in thisway that the well design and related components as well as theoperations related to installation can be reduced.

Some alternate embodiments comprise wired communication to the flowcontrol valve and sensor module. Referring to FIGS. 5 and 6, acommunication line (e.g., an electric cable, a hydraulic control line, apneumatic control line, a fiber optic cable, etc.) (22) from the flowcontrol valve and sensor module (23) is run to the surface and thenconnected to the existing infrastructure (24). For example, the flowcontrol valve is actuated by means of a communication line such as anelectrical control line conveying electric signals, a hydraulic lineconveying pressurized fluid, or a pneumatic control line containing anelectrical conductor conveying pressure and electrical signals. Thecommunication line (22) supplies power and/or communication to the valvefrom surface. A coiled tubing, small macaroni tubing, drill pipe,tubing, or umbilical hose bundle (25) could be used for conveying thecable and control line and/or actuating the valve. A communication line(22) is run from the valve to the surface for supplying power andcommunication to the valve from the surface. As an alternate embodiment,the communication line can supply communication to the valve from thesurface location with a power supply (e.g. long life battery or fuelcell) in the well to provide power to the valve.

Depending on the sand face completion (e.g. cased & perforated, standalone screen, expandable screen, pre packed screen, slotted pipe, openhole) the flow control valve, sand face completion, and cable can be runin a single run on coiled tubing, pipe, or tubing (25). In a completionrequiring two trips such as a frac pack completion or a gravel pack, awet connect could be provided in the lower completion for connecting thecommunication line from the surface. FIGS. 2 through to 6 showmulti-zone sand face completions that require more than one flow controlvalve.

As illustrated in FIG. 6, a multi-lateral well (26) has at least onebranch to connect more than one reservoir (23 and 27) to the existingreservoir (10).

While the invention has been disclosed with respect to a limited numberof embodiments, those skilled in the art will appreciate numerousmodifications and variations there from. It is intended that theappended claims cover all such modifications and variations as fallwithin the true spirit and scope of the invention.

1. A downhole completion system comprising: a wireless transmitter thattransmits a wireless signal from a surface location to a subsurfacelocation; a flow control device located along a flow path between tworeservoirs proximate the subsurface location; a sensor adjacent to theflow control device adapted to detect the wireless signal, wherein theflow control device is actuated in response to the detection of thewireless signal by the sensor, and wherein the wireless signal istransmitted through a strata between the surface location and thesubsurface location.
 2. The downhole system of claim 1, wherein thesensor and flow control valve are supplied with power from a downholepower supply.
 3. The downhole system of claim 1, wherein the sensor andflow control valve are supplied with power from a downhole powergenerator.
 4. The downhole system of claim 1, wherein the flow controldevice is connected with a communication line running from the surfacelocation, and wherein the communication line is adapted to supply theflow control device with power.
 5. The downhole system of claim 1,wherein the flow control device is a flow control valve, and wherein thewireless transmitter transmits a signal that is in a preset codedsequence that will actuate the valve.
 6. The downhole system of claim 1,wherein the wireless transmitter transmits a signal that is in a presetcoded sequence that will actuate the flow control device to open orclose.
 7. A method for actuating a flow control device, comprising:placing a flow control device between two reservoirs; transmitting asignal from a surface location to a borehole through a strata; detectingthe signal; communicating to the flow control device in a preset codedsequence adapted to actuate the valve; and actuating the flow controldevice when the sensor receives the signal.
 8. The method of claim 7,wherein the signal from the surface location to actuate the flow controldevice is at least one selected from the group consisting of: seismic,acoustic, pressure pulse, mud pulse and electromagnetic.
 9. The methodof claim 7, further comprising actuating the flow control devicerequiring the sensor to sense reservoir parameters and feed data to adownhole processor that sends a command to the flow control device toactuate the valve.
 10. The method of claim 7, further comprisingsupplying power to the flow control device from a battery or a fuel cellthat is run with the flow control device.
 11. The method of claim 7,further comprising supplying power to the flow control device from adownhole power supply.
 12. The method of claim 11, wherein the downholepower supply comprises a downhole power generator.
 13. A method ofproducing subterranean hydrocarbons comprising of: drilling andcompleting a primary well for producing a primary reservoir; drilling atleast one auxiliary well adjacent to the primary well; connecting theprimary reservoir to the marginal reservoir by extending the primarywell; completing the primary well to control fluid communication betweenthe primary reservoir and the marginal reservoir; and placing a flowcontrol device along a flow path between the primary reservoir and themarginal reservoir.
 14. A method of claim 13 further comprising placinga sensor adjacent to the flow control device.
 15. The method of claim13, further comprising actuating the flow control device via a cable ora control line from a surface location.
 16. A method of claim 13 whereinthe primary reservoir is connected to the marginal reservoir by drillingand completing a multilateral bridging well proximate the primary well.17. The method of claim 13, further comprising regulating flow of thefluid between the marginal reservoir and the primary reservoir with theflow control device.
 18. The method of claim 13, further comprisingsupplying power to the flow control device and downhole sensor using adownhole power supply.
 19. The method of claim 14, further comprisingdetecting a wireless signal using the sensor, wherein the flow controldevice is actuated in response to the wireless.
 20. The method of claim15, wherein the step of actuating the flow control device via a cable ora control line from a surface location is at least one step selectedfrom the group consisting of using an electrical control line to conveyelectric signals, using a hydraulic control line to convey pressurizedfluid, using a pneumatic control line containing an electrical conductorto convey pressure and electrical signals.